The present invention relates to a process for preparing emulsion polymers having a hollow structure. More specifically, the present invention relates to a process for preparing emulsion polymers which comprises forming an internal layer with an alkali-swellable resin, carrying out a subsequential emulsion polymerization by means of a continuous variation in composition and a kinetic steric barrier to form a hard polymer layer outside the internal layer, swelling the internal layer with an alkali and then drying to remove water contained in the alkali-swellable resin, thereby forming a closed internal pore in the center of the polymer particle.